Benzodiazepine whole blood concentrations in cases with positive oral fluid on-site screening test results using the DrugWipe(®) single for benzodiazepines.

Reliable on-site oral fluid screening devices are a useful and convenient means of policing traffic. In Finland, benzodiazepines represent a particular challenge to traffic safety. This study presents a retrospective examination of toxicological analysis results from whole blood in cases which gave a positive screening result for benzodiazepines in oral fluid using the DrugWipe Single device (Securetec). Use of oral fluid on-site screening tests and blood confirmation analyses reflects the real situation in many countries. The data were compiled from the databases of Alcohol and Drug Analytics Unit at the National Institute for Health and Welfare. Confirmation analysis results in whole blood were obtained using gas chromatography-mass spectrometry. Data were from 224 real cases in which the Finnish police had conducted a DrugWipe Single benzodiazepines test on drivers suspected of driving under the influence of drugs (DUID). The benzodiazepine concentrations encountered in positive oral fluid screening cases in this study indicate that the device is able to detect these substances even at relatively low levels. However, the DrugWipe device does not enable any distinction between therapeutic use and harmful use of benzodiazepines at higher doses.